Improvement in terrestrial globes



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N0. 168,514. I Patented Oct. 5,1875.

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- INT/'ENT @fr f l NFETERS. PHOTO-LITMQGRAPHER` WASHINGTON D C 2Sheets--Sheet 2 M. McVlGAR. Terrestrial-Globe.

Pa'fentd oct. 5,1875.

./ttorney,

N. PEIERS. PMOTO-LITHOGRAFHER. wAsmNGToN. D CA MALCOLM MGVIGAR, OFPOTSDAM, NFJW YORK.

IMPROVEMENT IN TERRESTRIAL GLOBES.

Specification forming part of Letters Patent No. 168,514, dated October5, 1875; application filed August 4, 1875.

To all whom t may concer/n:

Be it known that I, MALCOLM MGVICAR, of Potsdam, county of St. Lawrenceand State of New York, have invented certain new and useful Improvementsin Globes, of which the following is a specification:

My invention relates to globes used for purposes ofillustration ingeography and astronomy; and it consists in the construction of a globewith revolving equator, horizon, or circle of illumination, athree-quarter and a full meridian, a semicircle of illumination andtwilight, a semi-vertical circle, a pointer, and a circle correspondingin its general structure with the `horizon of ordinary globes, as willbe hereinafter more fully set forth.

In order to enable others skilled in the art to which my inventionappertains to make and use the same, I will now proceed to describe itsconstruction and operation, referring to the annexed drawing, whichforms a part of this specification, and in which- Figure l is a sideelevation, showing my invention. Fig. 2 is a side view, showing theglobe with revolving equator B, circle of illumination O, andthree-quarter meridian D in use. Fig. 3 is a side view, showing theparts 0f Fig. 2 in a different position, with the full meridian Eatt-ached. Fig. 4C is a section taken upon the line x of Fig. 3. Fig. 5is a detailed View, showing the manner of attaching full meridian E tothe circle G'.

A represents an ordinary terrestrial globe, such as are used for'purposes of illustration in geography and astronomy. B is a band orcircle of brass or other suitable material, designated the revolvingequator, which may revolve in a groove on the globe, or divide the globeinto the northern and southern hemi spheres, and revolve in the axis ofthe globe as a center. O is a circle, designated the horizon or circleof illumination, which is attached to the revolving equator B by twoscrews, a a, which form pivots on which it revolves. D is athree-quarter meridian, which is attached to the circle G ninety degreesfrom the pivots a a, and which extends one hundred and eighty degrees onone side and ninety degrees on the other side of the circle, passing onthe side where it is ninety degrees through an eye, d,

in the circle C, where, by means of a screw, E, it can be held inposition, and thus hold the circleO, to which it is attached, in anydesired position. The three-quarter meridian D is attached to the circleO by means of a screw, b, or otherwise. E is a full meridian, attachedby clamp-screws f f to a circle, G, which may stand horizontally, or atany desired angle to the horizon, and in which the axis h of the globeis fastened perpendicular to its face, or at any desired angle. By meansof the clamp-screws f and circle G the meridian can be moved into anydesired position. H and I are respectively semicircles of illuminationand twilight. They are attached to each other parallel, and at adistance of eighteen degrees. They are also attached by the screw b tothe inside of the meridian E, at a point one hundred and eighty degreesfrom that on which it revolves in the circle G. They revolve on thescrew b, and can be made to stand at any angle to the meridian E. K is asemi-prime vertical circle, attached by screws c and cl to the outsideof the meridian E, at points ninety degrees respectively from the pointon which the meridian turns on the circle G. L is a pointer, attached tothe meridian E near the point on which it turns on the circle G, anddirected to the degrees marked on the circle M. M is 'a circle, of anydesired size, parallel to the horizon, and placed at any convenientdistance below the circle G, having on its face a series of graduatedconcentric circles, such as are usually placed upon the .wooden horizon7 of ordinary globes.

The equator B is used to give to the horizon-circle C a free motion fromeast to west, and fiom west to east. By means of this motion and themotion of the circle C on its own axis, said circle can be madeinstantaneously to represent the horizon of any place on the globe;also, any position of the circle of illumination, the ecliptic, the eastand west circle of any place, and any great circle on the globe. Themeridian E and the semicircles H and I, the pointer L,and the circle Mare used Y in combination to show the change of the seasons, length ofday and night, and length ot' twilight, for any given place at any givenein time, apparent path of the sun, andthe places io which he Will bevertical on any given day of the year, and problems similar to these.

The meridian E and semi-prime vertical circle K are used in combinationto show the prime vertical of any given place, the relations of therising and setting sun to the east and-west, points of a place in anylatitude, and problems similar to these.

By the combination of the meridians D and E and circles B and C, allproblems can be solved that can be solved on any globe With the brassmeridian and Wooden horizon. All solutions can be made, also, With theglobe representing the real position of the earth, While with theordinary Wooden horizon the globe is constantly changed out of its realposition.

Having thus fully described my invention, what I claim as new, anddesire to secure by Letters Patent, is-

1. In a globe, the revolving equator B and circle C, suspended on theequator by the two points a a, so that, by its own motion on said pointsand the motion ofthe equator, the circle can be made to represent anygreat circle on the globe, substantially as set forth.

2. The movable three-quarter meridian D, fastened to the circle C,substantially as and for the purposes set forth.

3. A movable meridian, E, attached by a clamp-screw, in combination withthe circle G, standing horizontally or at any desired angle to thehorizon, and in which the axis of the globe is fastened perpendicular toits face, or at any desired angle, as herein set t'ortli.

4. The semicircles of illumination and twilight H and I, fastened to themovable meridian E, substantially as and for the purposes set forth.

5. The semi-prime vertical K, fastened to the movable meridian E,substantially as and for the purposes set forth.

6. The combination, With aglobe, A, of the movable equator B, pivotedcircle C, meridians D lE, semicireles of' illumination and twilight Hand I, semi-prime vertical K, pointer L, and the graduated circle M, allconstructed and arranged substantially as and for the purposes hereinset forth.

7. In a globe, a revolving equator, revolving independently of theglobe, but on the axis thereof as a center, substantially as shown anddescribed.

In testimony that I claim the foregoing as my invention, I hereuntoaffix my signature this 20th day of July, 1875.

MALCOLM MGVIGAR. Witnesses:

H. W. OsBoRN, W. E. OsBoRN.

